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Evolution of micro-damage and degradation of macro-mechanical properties of sandstone due to thermal effects
https://orcid.org/0000-0002-1512-3367
Abstract Previous studies on thermal induced damage of rocks concentrated mainly on the analysis of macro-mechanical properties. This paper documents physical and microstructural characteristics of sandstone after high-temperature treatment by using several testing methods at the micro scale. Results indicate that physical including mechanical parameters of tested sandstone show some strengthening effect up to a temperature of about 100 °C, which is related to the evaporation of free water and the thermal expansion of mineral particles. Beyond 100 °C, the physico-mechanical properties of sandstone are weakened significantly. Mass loss and porosity show a continuously growing with increasing temperature, while P-wave velocity, splitting tensile strength, compression strength, and elastic modulus are decreasing. Nuclear magnetic resonance (NMR) imaging tests were carried out to capture the variations in porosity and pore size distribution characteristics of sandstone during the heat treatment. With increasing temperature, the number of macropores and microcracks increase and coalesce. There is a linear relationship between rock porosity and tensile as well as compressive strength. Differential thermal analysis (DTA) shows that the α-β phase transition of quartz minerals occurs at a temperature of 573.4 °C. Additionally, between 400 and 600 °C, more transgranular microcracks are observed detected by optical microscope and scanning electron microscopy (SEM) observations, which proves that quartz phase transition is an important factor to induce microcracks. Thermal treatment also has a significant influence on the variation of the brittle index of sandstone, which makes thermal-induced plastic deformations of the sandstone more obvious.
Evolution of micro-damage and degradation of macro-mechanical properties of sandstone due to thermal effects
https://orcid.org/0000-0002-1512-3367
Abstract Previous studies on thermal induced damage of rocks concentrated mainly on the analysis of macro-mechanical properties. This paper documents physical and microstructural characteristics of sandstone after high-temperature treatment by using several testing methods at the micro scale. Results indicate that physical including mechanical parameters of tested sandstone show some strengthening effect up to a temperature of about 100 °C, which is related to the evaporation of free water and the thermal expansion of mineral particles. Beyond 100 °C, the physico-mechanical properties of sandstone are weakened significantly. Mass loss and porosity show a continuously growing with increasing temperature, while P-wave velocity, splitting tensile strength, compression strength, and elastic modulus are decreasing. Nuclear magnetic resonance (NMR) imaging tests were carried out to capture the variations in porosity and pore size distribution characteristics of sandstone during the heat treatment. With increasing temperature, the number of macropores and microcracks increase and coalesce. There is a linear relationship between rock porosity and tensile as well as compressive strength. Differential thermal analysis (DTA) shows that the α-β phase transition of quartz minerals occurs at a temperature of 573.4 °C. Additionally, between 400 and 600 °C, more transgranular microcracks are observed detected by optical microscope and scanning electron microscopy (SEM) observations, which proves that quartz phase transition is an important factor to induce microcracks. Thermal treatment also has a significant influence on the variation of the brittle index of sandstone, which makes thermal-induced plastic deformations of the sandstone more obvious.
Evolution of micro-damage and degradation of macro-mechanical properties of sandstone due to thermal effects
https://orcid.org/0000-0002-1512-3367
Abstract Previous studies on thermal induced damage of rocks concentrated mainly on the analysis of macro-mechanical properties. This paper documents physical and microstructural characteristics of sandstone after high-temperature treatment by using several testing methods at the micro scale. Results indicate that physical including mechanical parameters of tested sandstone show some strengthening effect up to a temperature of about 100 °C, which is related to the evaporation of free water and the thermal expansion of mineral particles. Beyond 100 °C, the physico-mechanical properties of sandstone are weakened significantly. Mass loss and porosity show a continuously growing with increasing temperature, while P-wave velocity, splitting tensile strength, compression strength, and elastic modulus are decreasing. Nuclear magnetic resonance (NMR) imaging tests were carried out to capture the variations in porosity and pore size distribution characteristics of sandstone during the heat treatment. With increasing temperature, the number of macropores and microcracks increase and coalesce. There is a linear relationship between rock porosity and tensile as well as compressive strength. Differential thermal analysis (DTA) shows that the α-β phase transition of quartz minerals occurs at a temperature of 573.4 °C. Additionally, between 400 and 600 °C, more transgranular microcracks are observed detected by optical microscope and scanning electron microscopy (SEM) observations, which proves that quartz phase transition is an important factor to induce microcracks. Thermal treatment also has a significant influence on the variation of the brittle index of sandstone, which makes thermal-induced plastic deformations of the sandstone more obvious.
Evolution of micro-damage and degradation of macro-mechanical properties of sandstone due to thermal effects
Wang, Pin (author) / Yin, Tubing (author) / Li, Xibing (author) / Konietzky, Heinz (author)
2023
Article (Journal)
Electronic Resource
English
BKL:
56.00$jBauwesen: Allgemeines
/
38.58
Geomechanik
/
38.58$jGeomechanik
/
56.20
Ingenieurgeologie, Bodenmechanik
/
56.00
Bauwesen: Allgemeines
/
56.20$jIngenieurgeologie$jBodenmechanik
RVK:
ELIB18
Inhomogeneous Micro-Structure Influence on Macro-Crack of Sandstone
| British Library Online Contents | 2013